The Southern Highlands is famous for its trees. Established English oaks, elms, and liquid ambers line the streets of Bowral and Burradoo. Significant pines and cypress stand on large lifestyle properties. Mature native eucalypts and she-oaks dot rural blocks across Wingecarribee Shire. When a pool sits near one of these trees, which happens frequently given that pools and trees were often planted around the same era in the 1970s and 1980s, pool removal requires careful planning to protect the tree’s root system from excavation damage.
Quick Answer (BLUF)
When removing a pool within or adjacent to a tree’s structural root zone (generally within a radius equal to 1.5× the trunk diameter in metres, as a rough guide), an arborist report is required before works begin. This report assesses whether excavation can proceed without critically damaging the tree, specifies how close machinery and excavation can safely approach, and may require hand-digging or root-pruning in the sensitive zone. In Wingecarribee Shire, trees protected by Tree Preservation Orders cannot be removed or significantly damaged without council approval, even if they’re causing problems.
Understanding Tree Root Systems
Tree roots extend far beyond the visible canopy. The structural root zone, where large buttress roots provide stability and major lateral roots carry water and nutrients, is the most critical zone to protect.
Rule of thumb for root protection distance: The Structural Root Zone (SRZ) radius in metres ≈ 12 × the trunk diameter at breast height (DBH) in metres.
For example:
- A tree with 40cm (0.4m) trunk diameter: SRZ radius ≈ 4.8m
- A tree with 80cm (0.8m) trunk diameter: SRZ radius ≈ 9.6m
- A large old oak with 120cm trunk diameter: SRZ radius ≈ 14.4m
Many Southern Highlands pools installed in the 1970s, 1980s are within the SRZ of large trees that were either already established or planted at a similar time. Forty years of growth has brought tree and pool into conflict.
Tree Protection Orders in Wingecarribee Shire
Wingecarribee Shire Council manages significant trees through tree management provisions in the Wingecarribee Development Control Plan (DCP). Trees above a certain trunk diameter or canopy spread may be subject to protection, requiring council approval before:
- Removal
- Root pruning within the SRZ
- Significant soil disturbance within the SRZ
The relevant DCP provisions specify which trees require approval and what the process involves. See the pool removal near trees and TPOs guide for the full regulatory picture.
Key point: Damaging a protected tree’s root system through excavation without approval is treated similarly to removing the tree without approval. Significant root damage may kill the tree over 1-5 years, tree death by excavation damage is as much a loss as tree removal.
When an Arborist Report Is Required
An arborist report from a qualified arborist (Level 5 AQF minimum under Australian standards) should be commissioned when:
- The pool is within 5m of any significant tree’s trunk
- The pool is within the canopy spread of any established tree
- The tree is protected by council’s DCP provisions
- The certifier issuing the CDC or DA requests one as a condition of approval
For many pool removal applications in Wingecarribee Shire near significant trees, the certifier will make an arborist report a mandatory condition of the CDC or DA before works proceed.
What the Arborist Report Covers
A Tree Impact Assessment for pool removal typically includes:
| Section | Content |
|---|---|
| Tree identification and condition | Species, DBH, height, canopy spread, health assessment |
| Root zone assessment | SRZ delineation, root distribution assessment, evidence of roots in pool area |
| Impact assessment | What excavation will do to root system; risk of tree decline or death |
| Recommendations | Exclusion zones, root pruning specifications, machinery restrictions |
| Mitigation measures | Hand-digging requirements, root barrier installation, irrigation during works |
| Post-works monitoring | Recommended monitoring period and indicators of tree stress |
A well-prepared arborist report gives the pool removal contractor a clear specification to work to. A vague report (or no report) leaves the contractor to make judgment calls that may damage trees or expose you to liability for unprotected tree damage.
Root Protection During Pool Removal
The arborist report will typically specify some combination of these protective measures:
Exclusion zone: An area around the tree within which no machinery, vehicles, or significant disturbance may occur. This may prevent excavation of part of the pool surrounds.
Hand-digging zone: An area where excavation must be done by hand (no machinery) to avoid root severance. This adds labour cost to the pool removal job.
Root pruning specification: If roots must be cut (e.g., to remove pool coping or surrounds), they must be cut cleanly with a sharp saw or secateurs at a specified minimum distance from the trunk, not ripped or torn by machinery.
Mulching and irrigation: During hot weather, exposed tree roots near the excavation should be mulched and watered to prevent desiccation stress while works are occurring.
Post-works inspection: Some arborists recommend a follow-up assessment 3-6 months after works to check for tree stress indicators (leaf wilting, branch dieback, bark damage).
The Cost of Arborist Requirements
Arborist requirements add cost to pool removal in several ways:
| Cost Item | Indicative Cost Addition |
|---|---|
| Arborist report (Tree Impact Assessment) | $600 to $2,000 |
| Hand-digging in root zone | $1,000 to $4,000 depending on area |
| Root pruning by arborist | $500 to $1,500 |
| Post-works monitoring inspection | $300 to $600 |
| Tree protection barriers during works | $300 to $800 |
| Extended coping removal (careful removal near roots) | $500 to $2,000 |
For pools positioned very close to a significant protected tree, the arborist-required works may add $3,000 to $8,000 to the overall removal cost. This should be factored into your project budget.
Trees Most Commonly at Risk Near Pools in the Southern Highlands
| Tree | Common Status in Southern Highlands | Risk from Pool Removal |
|---|---|---|
| English oak (Quercus robur) | Often protected by council DCP in Bowral and Mittagong streets | High sensitivity to root disturbance |
| Liquidambar (Liquidambar styraciflua) | Common in residential gardens, often significant size | Moderate sensitivity |
| Pin oak (Quercus palustris) | Common in Bowral heritage streets | High sensitivity |
| English elm (Ulmus procera) | Heritage areas of Bowral; protected | Very high sensitivity |
| Radiata pine (Pinus radiata) | Common on rural properties | Moderate; shallow roots can be severed without fatal effect |
| Blue gum (Eucalyptus globulus) | Rural blocks; protected native | Moderate; resprouting after root damage possible |
Planning the Pool Removal Scope Around the Tree
The tree’s position relative to the pool determines how much of the pool surrounds can be removed in the normal way and how much requires special treatment:
Scenario 1: Tree is outside the pool surrounds, within 5-8m of pool edge The pool itself can often be demolished normally. The coping and surrounds closest to the tree need careful hand-removal. The excavation boundary may need to stop short of the tree’s SRZ.
Scenario 2: Tree roots are already within the pool structure (cracking the pool) The pool is already compromised. Removal still requires care, cutting roots at the appropriate distance from the trunk, hand-digging to expose and cleanly cut roots before machine excavation of the remaining shell. See tree root intrusion and pool damage.
Scenario 3: Pool is almost entirely under or within the tree’s canopy Full removal of the pool may not be possible without significant root damage. Options include: partial removal (taking what can be safely accessed), modified approach with maximum hand-work, or in extreme cases, accepting that the pool cannot be fully removed without significant tree impact and choosing a partial fill-in instead.
Frequently Asked Questions
Do I need an arborist report for my pool removal if the tree is not protected? Not legally required for unprotected trees, but strongly advisable if any significant tree is within 5-8m of the pool. Damaging a tree’s root system, even an unprotected one, can cause it to die over several years, which is an unintended and potentially costly consequence.
Can an arborist say “no” to pool removal because of a tree? The arborist makes recommendations, they don’t approve or refuse the work. The certifier issuing your CDC or DA makes the approval decision, taking the arborist’s report into account. In very rare cases, a council DA may refuse pool removal because the approach proposed would critically damage a protected tree with no acceptable mitigation.
How do I find a qualified arborist in the Southern Highlands? Look for AQF Level 5 (arborist) qualification and registration with the International Society of Arboriculture (ISA) or Arboriculture Australia. Ask your pool removal contractor for a referral, or contact Wingecarribee Shire Council for their list of approved arborist assessors.
Will pool removal damage my tree’s roots even if we’re careful? Some root disturbance is likely when working close to a tree. An arborist-specified approach minimises this, clean cuts to roots at a safe distance, avoiding the SRZ with machinery, and protecting exposed roots during works. A healthy, well-established tree can recover from some root disturbance if managed correctly.
What if my neighbour’s tree is the one at risk from my pool removal? You have a common law responsibility not to damage a neighbouring tree’s root system without lawful authority. Discuss the situation with your contractor and arborist, and consider communicating with your neighbour before works proceed.
For pool removal safely managed around your established trees, contact Southern Highlands Pool Removals for an experienced site assessment.